Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Interpretation of prematurely terminated air-pressurized slug tests
An air-pressurized slug test consists of applying a constant pressure to the column of air in a well, monitoring the declining water level, and then releasing the air pressure and monitoring the recovering water level. Such tests offer a means of estimating formation transmissivity and storativity without extensive downhole equipment and the associated safety risks. This paper analyzes data from p
Authors
Allen M. Shapiro, Earl A. Greene
Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 2. Major structures
Polycarboxylic acid structures that account for the strong-acid characteristics (pKa1 near 2.0) were examined for fulvic acid from the Suwannee River. Studies of model compounds demonstrated that pKa values near 2.0 occur only if the a-ether or a-ester groups were in cyclic structures with two to three additional electronegative functional groups (carboxyl, ester, ketone, aromatic groups) at adjac
Authors
J. A. Leenheer, R. L. Wershaw, M.M. Reddy
Rapid toluene mineralization by aquifer microorganisms at Adak, Alaska: Implications for intrinsic bioremediation in cold environments
No abstract available.
Authors
P. M. Bradley, F. H. Chapelle
Fate, bioavailability and toxicity of silver in estuarine environments
The chemistry and bioavailability of Ag contribute to its high toxicity in marine and estuarine waters. Silver is unusual, in that both the dominant speciation reaction in seawater and the processes important in sorbing Ag in sediments favour enhanced bioavailability. Formation of a stable chloro complex favours dispersal of dissolved Ag, and the abundant chloro complex is available to biota. Sequ
Authors
S. N. Luoma, Y.B. Ho, G.W. Bryan
Partition of nonpolar organic pollutants from water to soil and sediment organic matters
The partition coefficients (Koc) of carbon tetrachloride and 1,2-dichlorobenzene between normal soil/sediment organic matter and water have been determined for a large set of soils, bed sediments, and suspended solids from the United States and the People's Republic of China. The Koc values for both solutes are quite invariant either for the soils or for the bed sediments; the values on bed sedime
Authors
Daniel E. Kile, C. T. Chiou, H. Zhou
Groundwater transport of crater-lake brine at Poas Volcano, Costa Rica
Poa´s Volcano is an active stratovolcano in Costa Rica that has a lake in its active crater. The crater lake has high temperatures (50–90 °C), high acidity (pH ≈ 0.0), and a high dissolved-solids content (100 g/kg). The volcano has numerous freshwater springs on its flanks, but a few on the northwestern flank are highly acidic (pH = 1.6–2.5) and have high dissolved-solids concentrations (2–22 g/kg
Authors
Ward E. Sanford, Leonard F. Konikow, Gary L. Rowe, Susan L. Brantley
Relations between pesticide use and riverine flux in the Mississippi River Basin
In an intensive subcontimental study of pesticides in surface waters of the United States, concentrations of 26 high-use pesticides were measured at nine sites in the Mississippi River basin from May 1991 through March 1992. Calculated total fluxes were combined with agricultural-use data to estimate the percentage of applied pesticide reaching the mouths of the Mississippi River and six major tri
Authors
Steven J. Larson, Paul D. Capel, Donald A. Goolsby, Steven D. Zaugg, Mark W. Sandstrom
Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 1. Minor structures
An investigation of the strong-acid characteristics (pKa 3.0 or less) of fulvic acid from the Suwannee River, Georgia, was conducted. Quantitative determinations were made for amino acid and sulfur-containing acid structures, oxalate half-ester structures, malonic acid structures, keto acid structures, and aromatic carboxyl-group structures. These determinations were made by using a variety of spe
Authors
J. A. Leenheer, R. L. Wershaw, M.M. Reddy
Use of the euryhaline bivalve Potamocorbula amurensis as a biosentinel species to assess trace metal contamination in San Francisco Bay
Potamocorbula amurensis was assessed as a biosentinel species in San Francisco Bay, California, USA. Uptake of metal in both the laboratory and field showed that P. amurensis was sufficiently responsive to Ag, Cd, Cr, Ni and V to detect environmental differences in exposure. It was less suitable as an indicator of Cu and Zn contamination. Concentration factors for P. amurensis were: Ag, 386000; Cd
Authors
C. L. Brown, S. N. Luoma
Fate of microbial metabolites of hydrocarbons in a coastal plain aquifer: The role of electron acceptors
A combined field and laboratory study was undertaken to understand the distribution and geochemical conditions that influence the prevalence of low molecular weight organic acids in groundwater of a shallow aquifer contaminated with gasoline. Aromatic hydrocarbons from gasoline were degraded by microbially mediated oxidation-reduction reactions, including reduction of nitrate, sulfate, and Fe(III)
Authors
I.M. Cozzarelli, J.S. Herman, M. Jo Baedecker
Pb2+ and Zn2+ adsorption by a natural aluminum- and iron-bearing surface coating on an aquifer sand
Pb2+ and Zn2+ adsorption was studied in batch experiments with material collected from a shallow, unconfined aquifer of glacial outwash sand and gravel in Falmouth, Massachusetts, USA. The aquifer solids contain primarily quartz (95% w/w), with minor amounts of alkali feldspars and ferromagnetic minerals. Pb2+ and Zn2+ adsorption experiments with various grain size and mineral fractions of the aqu
Authors
J.A. Coston, C. C. Fuller, J.A. Davis
Assessing nonpoint-source pollution risk: A GIS application
No abstract available.
Authors
Kenneth J. Lull, James A. Tindall, Donald F. Potts